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🔌General Home Automation => Original ActiveHome => Topic started by: robkwil61 on August 30, 2006, 10:29:38 AM

Title: CM11A - Weak transmission?
Post by: robkwil61 on August 30, 2006, 10:29:38 AM
I have an issue where a light switch module will turn on via the CM11A interface, but won't turn off.  It responds fine (on & off)  when using a palmpad controller.  If I move the CM11A to the same circuit as the light switch, it will work.  I have a phase coupling capacitor already installed across one of my 220 breakers. 

Any thoughts?

Thanks!
Title: Re: CM11A - Weak transmission?
Post by: dave w on August 30, 2006, 11:56:04 AM
Could be noise, and could also be weak coupling to the other phase. Is a "Coupler/Repeater" in your budget?

Title: Re: CM11A - Weak transmission?
Post by: robkwil61 on August 30, 2006, 02:18:16 PM
I would agree there is some type of interference.  Just seems there must be some difference in the signal strength of the CM11A vs a TM751.  The CM11A and the TM751 are plugged into the same circuit in the same room.  And the palmpad/TM751 works fine.

Probably would not buy a coupler/repeater... would probably just get another CM11A off eBay or buy AHP with the CM15A.

Thanks,
Rob
Title: Re: CM11A - Weak transmission?
Post by: Dan Lawrence on August 30, 2006, 02:25:51 PM
The CM11a is not a trancieving interface, so your PalmPad has no effect on it. The Palm Pad is talking to the 751, which controls the light.

BTW, as far as trancievers are considered, the RR501 is a more robust one than the TM751.
Title: Re: CM11A - Weak transmission?
Post by: robkwil61 on August 30, 2006, 04:02:33 PM
Actually, I am using a RR501.  My TM751 is on the back porch.  My mistake.

And yes, I realize the palmpad works with the tranciever, which the CM11a is not.  Thus my palmpad/tm751 comment.

So how well does the CM15A work as a tranciever?
Title: Re: CM11A - Weak transmission?
Post by: Dan Lawrence on August 30, 2006, 05:07:33 PM
The CM15A is a transponding interface, but many users have noted the antenna is too short (and doing any modifications to the antenna voids the warrenty, so you do it at your own risk). I use a RR501 in my Living Room to handle the signals from a Stick-a-Switch as the CM15A (which is 8 feet from the Stick-A-Switch) won't recieve the signals.

If your 501 works fine, keep using it, even if you move to AHP.  I did.
Title: Re: CM11A - Weak transmission?
Post by: Charles Sullivan on August 30, 2006, 05:45:06 PM
I would agree there is some type of interference.  Just seems there must be some difference in the signal strength of the CM11A vs a TM751.  The CM11A and the TM751 are plugged into the same circuit in the same room.  And the palmpad/TM751 works fine.

I haven't measured this myself, but have read that the powerline signal level transmitted by an RR501 or TM751 is substantially higher than that sent by the CM11A or CM15A, maybe by a factor of two.

A lot of signal strength problems are caused by newer electronic equipment like TV, PC, UPS, etc. which have switching power supplies.  These either introduce RF noise on the power line or act as "signal suckers" because of a large filter capacitance directly across their line input.  Try unplugging all appliances like this from the wall (merely turning off won't help) and retesting.  If you can identify an  offending appliance, a special X10 noise filter will solve the problem.
Title: Re: CM11A - Weak transmission?
Post by: Tuicemen on August 30, 2006, 05:49:49 PM
I never got very good range with credit card remotes or the Stick-A-Switch even before I moved to the CM15A
But I get over 100 feet with my palm pad and the CM15A without the modifications Dan mentioned seems newer homes or ones with new reno's have the most problem with the CM15A.
Dan : I'm curious as you live in an older home as I do (mine is close to 100 Years) has the home had any modern reno's which may be effecting the CM15A signals aluminum siding,foil backed insulationor steal studs? ???
Title: Re: CM11A - Weak transmission?
Post by: Dan Lawrence on August 30, 2006, 07:00:00 PM
I would agree there is some type of interference.  Just seems there must be some difference in the signal strength of the CM11A vs a TM751.  The CM11A and the TM751 are plugged into the same circuit in the same room.  And the palmpad/TM751 works fine.

I haven't measured this myself, but have read that the powerline signal level transmitted by an RR501 or TM751 is substantially higher than that sent by the CM11A or CM15A, maybe by a factor of two.

A lot of signal strength problems are caused by newer electronic equipment like TV, PC, UPS, etc. which have switching power supplies.  These either introduce RF noise on the power line or act as "signal suckers" because of a large filter capacitance directly across their line input.  Try unplugging all appliances like this from the wall (merely turning off won't help) and retesting.  If you can identify an  offending appliance, a special X10 noise filter will solve the problem.

I pulled my CM11A from the X10 Storage box and checked. There is no antenna or any provision for one. So, the CM11A can't send signals to any device like a Stick_a-Switch or recieve any from it.
Title: Re: CM11A - Weak transmission?
Post by: TakeTheActive on August 30, 2006, 07:22:25 PM
The CM11a is not a trancieving interface, so your PalmPad has no effect on it. The Palm Pad is talking to the 751, which controls the light.

While the END of this quote is correct, the BEGINNING is misleading.  ???

The CM11A *IS* a PLC Transceiver.

Please refer to this new LINK that I created: PLC / RF Transmitters, Receivers and Transceivers (http://www.x10community.com/forums/index.php?topic=9899.msg57801#msg57801)

BTW, as far as trancievers are considered, the RR501 is a more robust one than the TM751.

Experienced X-10 Users (aka "Old-Timers" ;) ) tend to prefer the RR501 over the TM751 because the RR501 contains a PLC Transceiver which allows it to listen to the line before it transmits (Collision Detection - it's polite . See the above LINK for more information. )
Title: Re: CM11A - Weak transmission?
Post by: TakeTheActive on August 30, 2006, 07:42:36 PM
Just seems there must be some difference in the signal strength of the CM11A vs a TM751.  The CM11A and the TM751 are plugged into the same circuit in the same room.  And the palmpad/TM751 works fine.

I haven't measured this myself, but have read that the powerline signal level transmitted by an RR501 or TM751 is substantially higher than that sent by the CM11A or CM15A, maybe by a factor of two.

I agree with Charles Sullivan on this - for a DETAILED CHART of the measured output voltages of most, if not all, of the X10-Manufactured PLC Transmitters, SEARCH the NEWSGROUP: comp.home.automation for articles by author 'Dave Houston'. He researched this topic a few years ago and documented his results.

You'll also find a few statements (somewhere in the same NG too!) that PLC TRANSMITTERS are actually SIGNAL SUCKERS themselves!  :o  [And plugging 4 of them into one 7-Outlet Power Strip will have an adverse effect. ]

(Jeff Volp will probably explain WHY to us all when he reads this.  :-* ).

Referring to your map of the circuits in your home (you did make one, right? ;) ) try:


Let us know if there are any differences.

A lot of signal strength problems are caused by newer electronic equipment like TV, PC, UPS, etc. which have switching power supplies.  These either introduce RF noise on the power line or act as "signal suckers" because of a large filter capacitance directly across their line input.  Try unplugging all appliances like this from the wall (merely turning off won't help) and retesting.  If you can identify an  offending appliance, a special X10 noise filter will solve the problem.

Yep!  8)

robkwil61,

Take a look at this New Troubleshooting Thread (http://www.x10community.com/forums/index.php?topic=9899.msg57582#msg57582) that I've been assembling and let me know if it helps you out.
Title: Re: CM11A - Weak transmission?
Post by: TakeTheActive on August 30, 2006, 08:48:46 PM
I pulled my CM11A from the X10 Storage box and checked. There is no antenna or any provision for one. So, the CM11A can't send signals to any device like a Stick_a-Switch or recieve any from it.

This statement is VERY misleading.

From it, a Newbie "could " incorrectly extrapolate (http://www.m-w.com/dictionary/extrapolate) that, since a CM15A *HAS* an antenna, it *CAN* send signals to a device like a Stick_a-Switch.  :(
Title: Re: CM11A - Weak transmission?
Post by: JeffVolp on August 30, 2006, 10:25:15 PM
Quote
You'll also find a few statements (somewhere in the same NG too!) that PLC TRANSMITTERS are actually SIGNAL SUCKERS themselves!

That is true.  The output circuit of virtually all X10 transmitters is always coupled to the power line.  When not transmitting, that circuit absorbs some energy from the line.  While certainly not as bad as electronic devices that have a capacitor directly across the line, several transmitters on the same circuit will significantly reduce X10 signal levels on that circuit.

Actually, many devices connected to the powerline will absorb some of the X10 signal, including X10 receiver modules.   Even though it may only be a few percent, it does add up in a large home with a lot of electrical devices.  I developed XTB to combat those distributed losses.

Title: Re: CM11A - Weak transmission?
Post by: Dan Lawrence on August 31, 2006, 08:47:28 AM
This is for TTA.

I looked at my old CM11A from Active Home days. There is NO antenna and NO provision for one. If you think the CM11a is a transieving interface, show me a pic of it.
Title: Re: CM11A - Weak transmission?
Post by: Charles Sullivan on August 31, 2006, 11:29:03 AM
Dan,
Please go back and reread the message of mine about relative signal strengths you quoted earlier.  I specifically mention POWERLINE signal levels.  No one is contending the CM11A has the capability for either sending or receiving RF.

It is possible for powerline signals to be swamped or corrupted by RF NOISE on the powerline - perhaps that's what threw you off.